Sorption of Ibuprofen to Coastal Plain Soils

Abstract

The transport and fate of pharmaceuticals and personal care products (PPCPs) in terrestrial and aquatic ecosystems has become an area of concern in the environmental science community. Due to advances in analytical technology, PPCPs have been detected in surface and groundwater at ng to [micro]g L-1 concentrations. Chronic exposure to PPCPs at these concentrations may have adverse effects on humans and aquatic organisms. The environmental fate of PPCPs is strongly influenced by their partitioning to soils, which is dependent on soil properties such as texture and organic matter content. However, few studies have examined the sorption of PPCPs to sandy, Coastal Plain soils containing low organic matter. Rapid subsurface PPCP transport may occur in Coastal Plain regions due to their characteristic permeable soils and seasonally high water tables. Laboratory batch studies were conducted in this study to evaluate the sorption of ibuprofen, a commonly used analgesic, to soils with varying physiochemical properties collected from discrete locations within North Carolina's Coastal Plain region. Sorption distribution coefficients (Kd values) were influenced by soil organic carbon content and ranged from 0.63-1.26 L kg-1. Empirical organic carbon normalized sorption coefficients, log Koc, for ibuprofen in Goldsboro, Norfolk, and Lynchburg soils were compared to theoretical estimates of its partitioning to soil organic matter (SOM). Results suggest that using such correlation equations may overestimate the partitioning of ibuprofen to SOM.